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Nikkor 12-24 vs. Canon 10-22 - Photography

In article <com>, net says...  It might exist someday. Wait until some cirstance arises where a defense lawyer has an opportunity to call the photo into question....

  1. #21

    Default Re: Nikkor 12-24 vs. Canon 10-22

    In article <com>, net
    says... 

    It might exist someday. Wait until some cirstance arises where a
    defense lawyer has an opportunity to call the photo into question.
    Brian Guest

  2. #22

    Default Re: Nikkor 12-24 vs. Canon 10-22

    "Brian C. Baird" <no> wrote in message
    news:verizon.net... 
    >
    > It might exist someday. Wait until some cirstance arises where a
    > defense lawyer has an opportunity to call the photo into question[/ref]

    It would take an incredibly big case and clear alteration of evidence to get
    long-standing legal precedent set aside.

    Walt


    Walt Guest

  3. #23

    Default Re: Nikkor 12-24 vs. Canon 10-22

    In article <stereo.hq.phicoh.net>,
    Philip Homburg <home.cs.vu.nl> wrote: 
    >
    >In the crypto world this is usually called a digital signature.
    >
    >The easiest way to do this is give each camera a small piece of
    >temperistant storage (for the key), and a certificate for the key.
    >(And updated firmware to compute signatures).
    >
    >No need for a dedicated memory card, or a secure card reader.
    >
    >The tricky part is of course to make sure that the key is well protected.[/ref]

    It would be simple enough to use a MD5 hash of a combination of
    the image and the camera's model number and serial number -- plus a
    private key hidden in the camera. This should suffice for a signature.
    (Hmm ... toss in the date too -- so that can be verified as well --
    compare the date stored in the image's info fields with that rolled into
    the MD5 hash, so a photo taken later could not be substituted.)
     

    The card could contain its own serial number, too. I presume
    that such are available on flash cards. They are certainly encoded in
    modern SCSI drives, and can be read by the system.

    Of course, something like PGP (or some other
    private-key/public-key cipher) would be better (more secure), but that
    would require more processing power in the camera -- perhaps taking the
    frame rate down to something like one frame per minute. :-)

    O.K. On a 300 MHz Ultra-SPARC CPU, a md5 hash of a 1.5 MB JPEG
    image takes:

    0.06u 0.04s 0:00.17 58.8%

    that is -- 60 mS of user time,
    40 mS of system time,
    or 0.17 seconds of wall clock time, with the CPU having
    58.8% of the system's resources at the time.

    A similarly fast and capable CPU in the camera would take something
    closer to the sum of the first two -- or 100 mS (0.1 seconds).

    A PGP signature would take somewhat longer, and a full PGP
    encryption of the entire file would take significantly longer -- so it
    depends on how much security you need -- and how much you are willing to
    accept that the encrypted image may become unrecoverable from a single
    bit error near the beginning. :-) I think that the PGP signature would
    be the best, with a private key in the camera (or the flash card), and a
    public key in the reader for verification. That way, it would not
    matter whether the reader was destroyed, as long as a record of the
    public key was available. And -- there is no real reason to keep the
    public key secret, so *anyone* could verify a copy of the image.

    Enjoy,
    DoN.
    --
    Email: <com> | Voice (all times): (703) 938-4564
    (too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
    --- Black Holes are where God is dividing by zero ---
    DoN. Guest

  4. #24

    Default Re: Nikkor 12-24 vs. Canon 10-22

    On Tue, 8 Mar 2005 19:53:57 -0500, "Walt Hanks"
    <net> wrote:
     
    >
    >I believe the OP indicated a preference for tripod-mounted long exposures,
    >not high ISO settings. Marty, is a little more digital noise going to
    >impact your work as a crime scene photographer?
    >
    >Walt
    >
    >[/ref]

    Walt,

    Actually I prefer high ISO, but tripod rather than flash. Last year I
    did one site which had very weak street lighting (using a
    tripod/self-timer with a mid range p&s) and had extremely high noise.
    Still, it was good enough to show the lighting situation. Its mostly a
    matter of pride that I want to reduce the noise as much as possible.
    Also, I was recently insulted by a street drug dealer who had a better
    camera than I did. :)

    Marty

    Marty Guest

  5. #25

    Default Re: Nikkor 12-24 vs. Canon 10-22


    "Marty" <netcom.com> wrote in message
    news:com... 

    Let me guess, Charles between Penn Station and North Ave? <g>

    Let us know what you decide to get. You might consider renting both for a
    day or two to see how they feel for you. I think that Service Photo (my
    favorite shutter shack) rents both systems. Just don't get Abe started on
    the Nikon/Canon stuff though. You'll be there for hours.

    Walt


    Walt Guest

  6. #26

    Default Re: Nikkor 12-24 vs. Canon 10-22

    Walt Hanks wrote: 
    >>
    >>It might exist someday. Wait until some cirstance arises where a
    >>defense lawyer has an opportunity to call the photo into question[/ref]
    >
    >
    > It would take an incredibly big case and clear alteration of evidence to get
    > long-standing legal precedent set aside.
    >
    > Walt[/ref]


    Well, it can still happen despite how slim the chances might be. The
    lawyers should start to get ready to prove their photographic evidents.
    leo Guest

  7. #27

    Default Re: Nikkor 12-24 vs. Canon 10-22

    On 8 Mar 2005 22:04:13 -0500, DoN. Nichols <com> wrote: 

    Make it SHA-256, in light of the recently discovered flaws in MD5
    and SHA-1. And how about tossing in GPS info as well?

    :-)
     

    You weren't speaking of a public-key system when you referred to a
    "private key"?
     

    I think the expensive part is the public-key math -- which is still
    not so bad since you're only signing a hash, not the message itself.
    (Ok, I'm handwaving here, I'm not actually sure which is more costly.)
     

    There's also no real reason to do that.
     

    Agreed, though it could just as easily be x.509.

    As my friend Thor pointed out to me when I was working on this,
    you can include the camera public key in the signed image, if you
    sign it with the vendor's private key. Then there's only one public
    key that everyone needs: the vendor's.

    I have some very nice diagrams of all of this that I commissioned
    when I still thought I was going to apply for a patent. :-) Talk
    about your expensive mistakes.

    --
    Ben Rosengart (212) 741-4400 x215
    Sometimes it only makes sense to focus our attention on those
    questions that are equal parts trivial and intriguing.
    --Josh Micah Marshall
    Ben Guest

  8. #28

    Default Re: Nikkor 12-24 vs. Canon 10-22

     

    Don,

    I have "played" with PGP since 2.6.2, so I at least know a little
    about what you are writing about. However, if it gets to all this I
    will go into the storage room and find my old Speed Graphic. It would
    be cheaper and simpler. :)

    Also, I usually have an assistant along (for measurements ... and a
    little extra firepower) and she would be available to testify as to
    the photographs as well. It has not been necessary yet.

    Marty ... who is (at this hour) leaning towards the XT due to the
    lower cost primarily. I will probably shoot at 10mm wide open and
    manual focus at just below infinity. With 10mm it all should fall into
    dof, even wide open. Naturally I can bracket ISO and/or shutter
    speeds. After a few tests I should know if I need a tripod or not. I
    am pretty steady for an old geezer and I usually have a car or pole or
    wall to use as a brace. I usually make three sets of 5x7s since I like
    the jury to have a set in their hands rather than looking across the
    room at larger prints (if they are awake). You cannot look at prints
    and pass them along while you are asleep. And I believe there is
    something personal about having them in their hands.

    Thanks,
    Marty


    Marty Guest

  9. #29

    Default Cryptographic image signatures (was: Re: Nikkor 12-24 vs. Canon 10-22)

    In article <panix.com>,
    Ben Rosengart <br+com> wrote: 
    >
    >Make it SHA-256, in light of the recently discovered flaws in MD5
    >and SHA-1.[/ref]

    O.K. I wasn't following that.
     

    Probably not a bad idea, if the camera is equipped to record GPS
    info into the image (something which would be useful in some fields --
    including your spies. :-)

     
    >
    >You weren't speaking of a public-key system when you referred to a
    >"private key"?[/ref]

    Not in the first instance -- just as something unique to the
    camera, and not predictable from the camera's serial number and model
    number. Maybe a hash of the owner's birthdate, plus other bits of
    information, or anything else, as long as it is not a known relationship
    to anyone else.

    Or even better -- a digitization of his/her right big toe
    (finger?)print. :-)
     
    >
    >I think the expensive part is the public-key math -- which is still
    >not so bad since you're only signing a hash, not the message itself.
    >(Ok, I'm handwaving here, I'm not actually sure which is more costly.)[/ref]

    Actually -- the most expensive, I believe, is the generation of
    the initial public-key/private-key pair -- at least based on the
    initialization of PGP.
     
    >
    >There's also no real reason to do that.[/ref]

    Agreed. Anyone should be able to examine the image, and to use
    it without needing to decrypt it. (Though your spy might like the
    encrypted version. :-)
     
    >
    >Agreed, though it could just as easily be x.509.[/ref]

    O.K. I was mentioning PGP as the one most easy to come by, and
    most familiar to me. (That and GPG.)
     

    O.K. If the public key is in the encrypted signature, and not
    in the unencrypted info.
     

    Sorry about that. Better luck with your next project.

    Enjoy,
    DoN.

    --
    Email: <com> | Voice (all times): (703) 938-4564
    (too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
    --- Black Holes are where God is dividing by zero ---
    DoN. Guest

  10. #30

    Default Re: Nikkor 12-24 vs. Canon 10-22

    On Tue, 8 Mar 2005 22:22:35 -0500, "Walt Hanks"
    <net> wrote:
     
    >
    >Let me guess, Charles between Penn Station and North Ave? <g>
    >
    >Let us know what you decide to get. You might consider renting both for a
    >day or two to see how they feel for you. I think that Service Photo (my
    >favorite shutter shack) rents both systems. Just don't get Abe started on
    >the Nikon/Canon stuff though. You'll be there for hours.
    >
    >Walt
    >[/ref]

    Hey Walt ... small world ain't it? I didn't know Service was still in
    business. I used to go there in the late sixties or early seventies
    when you were a kid. What do you shoot with? No jokes intended here.

    PS You know Charles Street is too well lit. :)
    Marty Guest

  11. #31

    Default Re: Nikkor 12-24 vs. Canon 10-22


    "Marty" <netcom.com> wrote in message
    news:com... 
    >>
    >>Let me guess, Charles between Penn Station and North Ave? <g>
    >>
    >>Let us know what you decide to get. You might consider renting both for a
    >>day or two to see how they feel for you. I think that Service Photo (my
    >>favorite shutter shack) rents both systems. Just don't get Abe started on
    >>the Nikon/Canon stuff though. You'll be there for hours.
    >>
    >>Walt
    >>[/ref]
    >
    > Hey Walt ... small world ain't it? I didn't know Service was still in
    > business. I used to go there in the late sixties or early seventies
    > when you were a kid. What do you shoot with? No jokes intended here.
    >
    > PS You know Charles Street is too well lit. :)[/ref]

    Service Photo is over on Falls road now. I shoot a Nikon N-70. I recently
    sold all of my old manual focus equipment and am watching and waiting to see
    what develops between now and when I can afford to buy something before I
    make a final decision on which digital system to buy into.

    Walt


    Walt Guest

  12. #32

    Default Re: Nikkor 12-24 vs. Canon 10-22

    On Tue, 8 Mar 2005 23:09:11 -0500, "Walt Hanks"
    <net> wrote:
     

    It used to be on Greenmount didn't it? About 3100 block?? That's when
    I was rolling my own Tri-X and it cost about 1 cent per negative that
    way. D-76 developer.
    Marty Guest

  13. #33

    Default Re: Nikkor 12-24 vs. Canon 10-22


    "Colin D" <127.0.0.1> wrote in message
    news:127.0.0.1... 
    >
    > I don't now whether you do this 'officially' for police or legal
    > reasons, but if you will be in a position to rely on your shots as
    > evidence in a court, you may be called on to prove the authenticity of
    > your pictures. A negative is generally regarded as incontrovertible
    > proof of authenticity, but the ease with which digital images can be
    > tampered with generally means it is harder to prove the image as
    > genuine.
    >
    > Canon is working on (may have it on the market now, as I haven't been
    > following the progress) a system that will be proof of authenticity for
    > a digital image, for the reasons outlined above. I am unaware of any
    > move in that direction by Nikon, or any other maker of digital cameras.
    >[/ref]

    20D has this security feature. If you are shooting professionally, I would
    go with 20D or even 1D MkII, since you can claim it as a business cost.
     


    Musty Guest

  14. #34

    Default Re: Cryptographic image signatures (was: Re: Nikkor 12-24 vs. Canon 10-22)

    On 8 Mar 2005 22:54:52 -0500, DoN. Nichols <com> wrote: 

    Fortunately that doesn't have to be done in the camera.
     
    >
    > O.K. If the public key is in the encrypted signature, and not
    > in the unencrypted info.[/ref]

    No reason for the public key to be encrypted. It's public. It just
    needs to be signed.
     
    >
    > Sorry about that. Better luck with your next project.[/ref]

    Thanks. I can't really complain: I had fun, and maybe some day I'll
    get to use what I learned about the patent system.

    --
    Ben Rosengart (212) 741-4400 x215
    Sometimes it only makes sense to focus our attention on those
    questions that are equal parts trivial and intriguing.
    --Josh Micah Marshall
    Ben Guest

  15. #35

    Default Re: Nikkor 12-24 vs. Canon 10-22

    In article <com>,
    Marty <netcom.com> wrote: [/ref]

    [ ... ]
     

    Sorry -- I got carried away with the "how" even after the need
    had been proven to be not present.
     

    Good enough.
     

    Of course your effective focal length (as determined by your
    coverage) will be 16mm, as contarasted with the 18mm for the Nikon with
    its widest setting being 12mm. But presumably, this should be
    sufficient.

    [ ... ]
     

    Have you ever had problems with the jury being confused by the
    perspective that you get with a really wide lens?

    Good Luck,
    DoN.

    --
    Email: <com> | Voice (all times): (703) 938-4564
    (too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
    --- Black Holes are where God is dividing by zero ---
    DoN. Guest

  16. #36

    Default Re: Cryptographic image signatures (was: Re: Nikkor 12-24 vs. Canon 10-22)

    In article <panix.com>,
    Ben Rosengart <br+com> wrote: 
    >
    >Fortunately that doesn't have to be done in the camera.[/ref]

    Amen!
     
    >>
    >> O.K. If the public key is in the encrypted signature, and not
    >> in the unencrypted info.[/ref]
    >
    >No reason for the public key to be encrypted. It's public. It just
    >needs to be signed.[/ref]

    You're right. I was thinking private key for whatever reason,
    instead of reading what you actually wrote.
     
    >>
    >> Sorry about that. Better luck with your next project.[/ref]
    >
    >Thanks. I can't really complain: I had fun, and maybe some day I'll
    >get to use what I learned about the patent system.[/ref]

    My experience with it came at no cost (and no gain) to me. I
    was working for an Army R&D lab at the time, and they paid for the
    patent processing, and provided the legal expertise. Of course, they
    got the rights to use it for Government purposes, and only if there was
    a private enterprise application would I get any possible royalties. Of
    course, there weren't. :-)

    Enjoy,
    DoN.

    --
    Email: <com> | Voice (all times): (703) 938-4564
    (too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
    --- Black Holes are where God is dividing by zero ---
    DoN. Guest

  17. #37

    Default Re: Nikkor 12-24 vs. Canon 10-22

    2005-03-08, Ben Rosengart wrote: 
    >
    > It's out there; in its second version, even. The part is the DVK-E2.
    > The press release says it works with the 1Ds and the 1D MkII. I'd
    > guess it works with the 1Ds MkII as well. Somewhere on dpreview, it
    > says that this thing works with the 20D, but I have a 20D and I
    > don't believe that that's correct.
    >
    > http://www.dpreview.com/news/0401/04012903canondvke2.asp[/ref]

    So, how does it work? I cannot find any details.
     

    You and me both....

    -peter

    Peter Guest

  18. #38

    Default Re: Nikkor 12-24 vs. Canon 10-22

    In article <panix.com>,
    Ben Rosengart <br+com> wrote: 

    On a low-end system (say Pentium-133) with slightly optimized C code,
    computing a SHA-256 hash is about 1 Mbyte/s. Computing a 2048-bit RSA
    signature takes about 5 seconds.

    I don't know how fast the CPUs are that they put cameras.

    --
    That was it. Done. The faulty Monk was turned out into the desert where it
    could believe what it liked, including the idea that it bad been done by.
    It was allowed to keep its horse, since horses where so cheap to make.
    -- Douglas Adams in Dirk Gently's Holistic Detective Agency
    Philip Guest

  19. Moderated Post

    Default Re: Nikkor 12-24 vs. Canon 10-22

    Removed by Administrator
    Marty Guest
    Moderated Post

  20. #40

    Default Re: Nikkor 12-24 vs. Canon 10-22

    In article <com>, net
    says... 
    >
    > It would take an incredibly big case and clear alteration of evidence to get
    > long-standing legal precedent set aside.[/ref]

    I'm sure of it. But things have a funny way of coming about.

    What if a journalist snapped photos of a crime in progress with a
    digital camera and those photos were used as evidence, much as closed-
    circuit video footage is? Would someone dare accuse the photographer of
    digital manipulation, and would the judge be stupid enough to believe
    him?
    Brian Guest

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